If it's not open it's broken.

LineageOS Publishes First Document in Public Charter

There’s no custom Android ROM out there that’s more dependable than LineageOS. It’s actually the only custom ROM that I know of with a working built-in updater—flash it once (with the optional root binary) and you can take OTA updates as they come without ever having to flash a full ROM again.

Camera – all devices with Camera supported in their stock OS MUST support Camera, in both front facing and rear camera configurations.

CVE – devices MUST support CVE patches for “high profile” exploits and vulnerabilities (if the media is reporting on it, then we must have it patched).

Encryption – all devices MUST support software encryption.

Root (su) – all devices MUST NOT ship with su included. All devices MUST support su installation via LineageOS provided ‘Extras’ download.

Wiki – all devices with a shipping build of LineageOS MUST have a wiki page with valid installation instructions.

I think it’s pretty great to see a custom ROM so dedicated to user experience and transparency. You can read more about the charter—and see the actual document for yourself—at the links immediately below.